I was glancing at an old National Theatre programme the other day and two names leaped out at me. Among the cast listing for "sailors, servants etc" in a 1965 production of Congreve's Love for Love, I noticed Anthony Hopkins and Mike Gambon (as he then was). Both rose spectacularly from the ranks, became acting heavyweights and achieved knighthoods. But where Hopkins virtually forsook the stage to become a Hollywood star, Gambon has combined theatre, film and television to become one of of our most cherished actors. He's not merely liked; he's loved.

Gambon, it's fair to say, is not an actor who enjoys analysing his craft in public: he's a doer rather than a theorist and deflects searching questions with often hilarious anecdotes. He will, however, talk about memory loss – and, for all his anxieties, it's worth scotching the rumour that he's quitting the stage for good. "I find it difficult to remember lines," he told me when I interviewed him at the recent HighTide festival in Suffolk. "When I'm doing a long speech for television, I sometimes have an earpiece with someone feeding me the text. But I can get by in the theatre if I study hard for a couple of months.

"I saw Trevor Nunn the other day and he said he's got a part coming up for me. I told him I'd be very good playing a butler who comes on now and again when the phone rings but who's so old he can't actually find the phone. Trevor said it wasn't a butler he had in mind. But I'm still doing theatre and performing Beckett's Eh Joe when asked. That's brilliant, because I don't have to speak, just sit on the edge of a bed while a camera records my facial movements as I listen to a pre-recorded female voice. I reckon I could take that anywhere in the world."

At the climax of Eh Joe the camera moves in on a gigantic close-up of Gambon's face as he cries at the recollection of the havoc he has caused. But how does one cry on cue? "You just do it," says Gambon. "That's what acting is. But I admit I try and summon up a powerful image. The one I often think of is that of a little girl in uniform, taken during the Vietnam war, with her clothes and body on fire because of an aerial bomb. I believe she recovered and is now a doctor, which makes me feel I'm not simply exploiting someone else's tragedy."

Gambon in The Singing Detective by Dennis Potter in 1986 PR

The idea that there is a pragmatic solution to a role's emotional demands is quintessential Gambon. If I were pressed to explain the source of his success, I'd say it springs from a rare combination of awesome lung power, emotional transparency, unfettered imagination and physical precision. For him acting is a craft as well as an art, a high-definition skill as well as a lifelong obsession. He came to London from his native Dublin at the end of the second world war, and he went on to become a qualified tool-maker with Vickers Armstrong. He brings a similar attention to detail to his acting; and it's revealing that the people he most admires in theatre are those who possess an instinctive practicality.

"I fell in love with Alan Ayckbourn," he says, "the day I met him and, starting with The Norman Conquests, went on to do eight plays with him. He tells you just what you want to know and has a brilliant way of solving problems. I suppose our most famous partnership was when he directed me as Eddie in Arthur Miller's A View from the Bridge at the National. Eddie is a violent man, and one day in rehearsal Alan told me to pick up a table and hurl it with full force at my wife and niece. He said, 'You can't hurt them because they're in a corner.' Anyway, everyone who saw it said the effect was sensational and some time later I asked Alan why he thought of it. 'Well,' he said, 'I had to find a way of clearing the table in time for the next scene.'"

Gambon worships skilled practitioners. He recalls how, when he was a young actor at the National, Olivier told him always to enter with his upstage foot first, because it was more decisive, and to learn to play out front to an audience rather than always listening intently to the other characters: a priceless reminder that acting is about showmanship as well as psychological truth.

His reverence for Harold Pinter also stems from the precison of his texts and the practicality of his advice. When Gambon was in Old Times in Guildford, Pinter came to see the production and gave the actor a post-play bollocking. "You're not meant to be a ballet dancer," he said. When Gambon protested, Pinter replied: "You look like a bleeding ballet dancer to me, mate."

Michael Gambon and Marlon Brando in Dry White Season from 1989. Photograph: MGM/Everett/Rex

That was typically perceptive of Pinter, since not only does Gambon admit he was playing the role a bit camp, but he also has that fleetness of foot you often find in heavily built men. I always recall a moment in David Hare's Skylight when he seemed to float across the stage in a state of post-coital bliss. But what really astonishes me is the revelation that he almost became, albeit temporarily, part of the Royal Ballet. "When I was doing Tales from Hollyood at the National," he says, "I was invited to dinner by the choreographer, Kenneth MacMillan. He told me I had the heart of a dancer, and asked me if I'd like to come on at the end of Romeo and Juliet as a friar. I said I'd love to but, sadly, MacMillan died shortly after. But a costume was made for me and I like to think it's still there, with my name on it, in the Royal Ballet wardrobe."

Gambon may not have become a dancer but he's done just about everything else. He has given us a host of unforgettable performances, ranging from Brecht's Galileo to Miller's Eddie Carbone and the father in Caryl Churchill's A Number. His TV credits fill several columns and, in addition to his landmark role in Dennis Potter's The Singing Detective, I always think of him in a brilliant adaptation of Elizabeth Bowen's The Heat of the Day (scripted by Pinter) in which he played a wartime spy secretly falling in love with his female quarry. On film he is now world famous as the Hogwarts headmaster Albus Dumbledore in the Harry Potter series, and he is proud of the fact that he has worked with three of his great screen heroes: Brando, De Niro and Pacino (or "the three Os", as he calls them).

Off screen, he is also a passionate collector. He has 400 antique pistols, dating from 1660 to 1820 and occupying five floor-to-ceiling cabinets, as well as a large collection of clocks. On top of that, he is a qualified private pilot and, to this day, still does what he calls "circuits and bumps".

In his acting career, one is tempted to say there have been lots of circuits and very few bumps.

• Michael Gambon stars in Quirke, which starts on 25 May, 9pm on BBC One